Carpet Protection Suggestions?(DIY maybe?)

First off sorry, wasn't sure where to put this. If a mod knows where it should be please feel free to move it.

Anyways I'm currently awaiting a new fancy pants HM Aeron chair. I've been using a desk chair for years that could possibly have been the birth of racing style "gamer" chairs(AK Octane cloth fabric). And it's probably lasted better than some of those would anyways. It has rollerblade style wheels that absolutely flattened the previous carpet, which was quite old anyways and has long since been replaced. Since then I've used those plastic mats, always the thickest I could get, that are supposed to protect the carpet. I've probably gone through 3 now, first they start to bow which is nice if you want the chair to stay put, then they crack.

Now to the point of this thread I guess. Having not had a chair with the style of castors that the Aeron has I don't know how well they do on carpet and whether I should just go naked carpet or not. So, if I should continue to do something on my carpet what are some ideas, or things you've done? I've heard people say they used left over carpet to make a carpet to throw on top(yo dawg...). Though I'll admit I like that the mat makes rolling around easier. I also remember reading a while back on some forum thread(elsewhere) I can't seem to find again that someone had gone to a hardware store and had them cut out some sort of flooring if I recall correctly, and threw it on top of their old mat. They claimed it seemed to be doing better than any mat had done in the past. If only I knew what it was, or possibilities of what might work.

Well to answer a question with another question: why would u use a carpet under a chair?
If it's one of those whole floor carpets u just have to either cut out a piece or throw a hard surface on the mat.
I'd prolly build a laminated section where the workdesk is.

Yes the whole floor is carpet. As well, being it's not my house, I can't do anything of the sort in terms of just slicing up the carpet.

Plexi glass is very sturdy.
http://www.homedepot.com/p/48-in-x-96-in-x-1-8-in-Acrylic-Sheet-MC-100/202038054

There are also cheaper and thinner plastic variants available, like this one: http://www.ikea.com/us/en/catalog/products/44881100/
But of course, if you've already burned through three of those...

There are also rubber mats, but those will most likely stain the carpet when rubbing against it.

Just remember to weather and beat the mat once in a while, so you don't get any permanent depressions in the carpet.

Admittedly the 3 I've burned through each probably has lasted 2 years give or take. But as I said, they were the thickest possible at officemax. If I recall correctly the thread I found may have spoke of laminate flooring but really not sure, maybe I'll attempt to find it again. Thanks for the suggestions though.

I know this is an old thread but what about the plastic tiles that snap together and have rounded edge pieces? You see them in businesses and sometimes people garages?

Yeah, I think when I was looking around I found some doing something like that, or the fake or real wood pieces. Most seem to use something like plywood or anything similarly cheap and throw some sort of flooring on top, as well as doing something to the bottom to protect the carpet(urethane coating for example). I have yet to make a decision on what I'm going to do if anything...my biggest issue is the tools for the job.